While photographs and family videos of a newborn baby evolve into a delicate-featured young boy, a man's voice conveys a range of emotions. "I knew he'd be victimized at some point," says David Long, Tyler's father. These are the opening moments of Bully (in theaters March 30), a timely, compelling, yet often difficult-to-watch documentary by Emmy Award-winning filmmaker Lee Hirsch that weaves together stories of five children who've endured extreme abuse from their peers. David chokes up as he wishes Tyler would walk through the door again, but the boy has committed suicide.

Bully is a deeply personal film for Hirsch. "I was bullied throughout middle school and much of my childhood," the director recalls. "In many ways, those experiences and struggles helped shape my worldview and my direction as a filmmaker."

Hirsch documents numerous stories — including one of a 16-year-old lesbian who after coming out was ostracized along with her family by her entire town — but one child emerges as the film's clear protagonist. Alex, a gentle-natured, bespectacled seventh-grade boy in Sioux City, Iowa, finds there's no more terrifying place than the school bus. For him, the ride to and from his middle school each day is hellish — filled with cruel taunts and pencil jabs, even being "strangled," as he puts it, by older students. When his worried father asks about his day, Alex tries to assuage the concerns of his parents by saying the other kids were "just messing with" him. Hirsch traveled on the bus with Alex, and while he was legally prohibited from physically interceding, he became so alarmed by the abuse he witnessed that he took the footage to Alex's parents, the school, and the local police department.

In another harrowing scene, in Perkins, Okla., a boy sobs while leaning against the open coffin of his best friend, 11-year-old Ty Smalley, who committed suicide after being bullied. Ty's father, who describes himself as a simple man, learned to use the Internet so that he could launch a nonprofit antibullying organization, Stand for the Silent.

Bully examines the grim consequences of a crisis confronting our country through the stories of these young people and demands change in the way we deal with bullying as parents, teachers, and society as a whole.